The ever-increasing demand for smaller sized mobile devices, such as cell phones, digital cameras, etc. correspondingly triggered a growing need for a smaller sized photography module, comprising elements such as an optical imaging lens, a module housing unit, and an image sensor, etc., contained therein. Size reductions may be contributed from various aspects of the mobile devices, which includes not only the charge coupled device (CCD) and the complementary metal-oxide semiconductor (CMOS), but also the optical imaging lens mounted therein. When reducing the size of the optical imaging lens, however, achieving good optical characteristics becomes a challenging problem.
Please refer to FIG. 1, which shows the structure of traditional lens elements 121, 122, 123, 124 in a traditional optical imaging lens 1. For meeting the aforesaid requirement of reducing the thicknesses of the lens elements, the traditional lens elements 121, 122, 123, 124 are shaped in great diameter and finest thickness. Each of the traditional lens elements 121, 122, 123, 124, positioned in a lens barrel 11 without contacting with each other, has a lens portion for passing imaging light and a peripheral portion formed around the lens portion and extending to the rim of the lens element. As shown in FIG. 1, the lens portions 121A, 122A, 123A, 124A is formed with concave and/or convex shape for generating predetermined optical effect, and the thicknesses of the peripheral portions 121B, 122B, 123B, 124B at the outside of the lens portions 121A, 122A, 123A, 124A are quite thin. Forming the thickness such thin in the place which is near the rim will be a great challenge in the manufacture procedure. Thus, in the reality, the peripheral portions 121B, 122B, 123B, 124B are easily to get broken when the lens elements 121, 122, 123, 124 are removed from the molds, and consequently, the yield will be decreased.
Therefore, there is needed to lower the possibility of breaking lens elements in the manufacturing procedure and develop lens elements, with a slim size, while also having good optical characters.